Wildfire smoke — the Silverado/Bond defining pattern.
The October 2020 Silverado Fire burned to the edge of Portola Springs and Orchard Hills, forcing evacuations, and the December 2020 Bond Fire burned Silverado Canyon east of Irvine. HVAC systems community-wide pulled wildfire smoke composite — burned structures, plastics, vehicles, and household contents mixed with wildland fuels — into master-planned homes, multi-family complexes, and tech commercial spaces. Attic insulation, soft goods, and porous materials absorbed heavily.